Remote control for radioreceivers



Oct? 1932- B. WASHINGTON-ET AL 1,881,391

REMOTE CONTROL FOR RADIORECEIVERS Filed June 15, 1927 Patented Oct. 4,1932 sTTEs ."BOWIDEN WASHINGTON, OF NEW YORK, AND WILSON .A'ULL, JR., OF.ASTORIA; NEW YORK, ASSIGNORS TO REMOTROLE CORPORATION, A CORPORATION OFNEW YORK REMOTE CONTROL FOR RADIOREGEIVERS Application filed June 13,1927. Serial No. 198,470.

One object of our invention is to provide a simple and easy manner ofturning on and off the filaments of a radio receiver from the loudspeaker no matter where the latter may be located, and without causing adrop of filament voltage at the vacuum tubes which would be the case ifthe filament current was caused to flow through long extension wires .p

of small cross section.

Another object is to be able to control from a point near the loudspeaker the volume of the sound produced withoutspoiling the quality.

It is becoming more and more usual to use extension cords sometimes ofconsiderable length in which case the listener hasto go to the receiverto turn off the filaments. A particular instance of this may be given toshow its usefulness in the broadcasting of morning exercises. In thiscase the radio receiver would normally be placed in the living room,while the user might desire to take exercises in his own room or on aporch immediately upon arising. By means of our invention he couldbefore retiring tune to the station which normally transmits thematerial for the morning exercises and bring the loud speaker to theexercisingplace. Upon arising at the predetermined hour he would lightthe filaments of his receiver from or at the loud speaker, thus puttingthe set into operation and upon finishing the exercises turn off thefilaments without the necessity of going downstairs or into another roomwhere the receiver is located.

The drawing shows one form of our invention applied to a radio receiverhaving direct audio frequency out-put.

Referring to the drawing the plate 5 of the last audio frequencyamplifier tube 6 of the set is connected in the usual manner to one wireof the extension cord 7 terminating in a plug socket or jack 8. Thespeaker 9 by its cord 10 is connected to the usual plug 11.

' The positive terminal of the B power pp y such as battery 12 isconnected in the usual manner to one conductor of the cord 7.

The relay 13 is of low resistance and may be of the delay type in orderto have a time response factor suited to the desired sefilaments. It isconnected in series with the.

Abattery 1a and the filaments. It is normalvly held in the closedposition by thespring 15. The relay 16 is of comparatively higherresistance and may be operated by the direct current'componentof theloud speaker. in-

ut., It isnormally held open ,by the spring 17. The resistance 18 ispreferably of the general order of value of the plate filament impedanceofthetube'- 6. In orderto control the volume preferably withoutaifectingthe plate'voltage we may provide a transformer 19 in-theloudspeaker circuit with a voltage :divider or potentiometer 20 across ,thesec- .ondary so arranged that any :desired fractiona1part of thevoltagemay berdelivered -to thelloud speaker 9 or the current to thespeakervmay be. turned off.

:Inoperation when the plug 11 is inserted Einto the jack Scurrentfromthe B battery 12 goes through the loudspeaker and-back through theresistance 18,1through the con- :tacts ;of' the relay 13 i and throughthe wind ings of the relay 16 back tothe battery, thus .energizingthemagnet ofthe relay 16.,and closing its contacts. When this closure is-eifected,-the filaments are heated but it Will be seen that in serieswith these filaments is ;the low resistance relay 13 which becomes s:

The plug and jack serve as a switch to interrupt and or close the loudspeaker circuit.

Suitable by-pass condensers (not shown) may be employed in parallel withany or all of the relays or resistances used in order to reduce signalloss therein, as well known in the art.

Household wiring and piping systems may be utilized in whole or in partfor the extension conductors 7 The transformer, potentiometer and plugswitch may be sold and mounted as a single unit either for insertionbetween the receiver and the speaker or to be connected by an extensioncord to the speaker base.

It should be understood that other modifications may be made within thebroad scope of our invention. tails of the radio receiver and the typeof loud speaker are immaterial.

We claim: 7

1. In a vacuum tube radio receiver having a loud speaker, thecombination of a switch in the loud speaker circuit, a relay having acoil in the plate circuit and having a switch member in the filamentcircuit, the current in the plate circuit being normally sufficienttohold the filament circuit closed, a relay having a coil in the filamentcircuit and a switch in an auxiliary plate circuit and a substantiallyconstant impedance Volume control deriving its energy input from theconductors supplying the first mentioned switch in the loud speakercircuit.-

2. A vacuum tube radio receiver having an A battery, a B battery and aloud speaker, a relay connected to the A battery, a switch and volumecontrol of substantially constant impedance located at the loud speaker,said switch, volume control and loud speaker being connected to theradio receiver by a a single pair of conductors and circuit connectionsfor closing the B battery circuitand automatically operating the relayand lighting the filaments when said switch is closed including a switchand anoperating coil in the filament circuit.

3. A radio receiver combination adapted for distant control including aradio receiver having electronic tubes, a source of cathode heatingpotential and a source of anode potential furnishingv energy thereto, ashunt circuit from the cathode source to the anode source, a lightingrelay with its operating coil in the anode circuit and its contactsclosing the filament circuit, and a cut-ofi relay with its operatingcoil in the filament circuit and its contacts opening said shunt circuitso that normal space current flow is established upon its operation.

BOWDEN WASHINGTON. WILSON AULL, JR.

Obviously the de-

